The LP78090 is a monolithic linear battery charger whit smart power path switch for single-cell Li-ion batteries in a wide range of tablet and other portable devices. It integrates a linear regulated voltage for power the system and charging the battery at the same time. This device supports both USB and high power DC adapter input. Its charger is a complete constant-current constant voltage linear charger with adjustable charge current up to 1000mA. No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be ISET rammed externally with a single resistor. The charger automatically terminates the charge cycle when the charge current drops to 1/10th the ISET rammed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the LP78090 automatically enters a low current state, dropping the battery drain current to less than 15μA. When connecting a high power DC adapter, the smart power path management allows LP78090 power the system with VIN voltage or BAT voltage by switching the voltage level on SC pin and charge the battery simultaneously. This allows immediate system operation even under moving away or deeply discharged battery. When the input current limit is reached, the voltage applied on the SYS pin would pull down to the battery voltage making the charge current decrease. If the current out of SYS pin is more than charge current plus 1200mA, LP78090 with turn power adapter and battery support the system load together. The LP78090 provides an internal path from battery to system in the event the input is removed. Other features include charge current monitor, under voltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage.